Location based access control for content delivery network resources

ABSTRACT

Mechanisms are provided to allow efficient delivery of content through a content delivery network (CDN) without taxing an origin server while maintaining fine grained location based access control. Requests to a CDN are augmented with quantized and non-quantized versions of location information. A CDN can use quantized location information in a URI to identify and return content if content corresponding to the URI is available in cache. If the content is not available in cache, the CDN can contact an origin server to obtain a result for the request using non-quantized location information. The origin server examines the non-quantized location information to determine whether to respond to the client request with content. The origin server examines the area corresponding to the quantized location information to determine whether the content should be cached at the CDN.

TECHNICAL FIELD

The present disclosure relates to a mechanism for providing locationbased access control for content delivery network resources.

DESCRIPTION OF RELATED ART

It is often desirable to use content delivery networks (CDNs) todistribute resources such as media content to clients. CDNs havescalable network and server capacity to meet client demand. However,CDNs do not typically allow for fine grained access control toresources. Consequently, the techniques and mechanisms of the presentinvention provide improved mechanisms for providing location basedaccess control.

OVERVIEW

Mechanisms are provided to allow efficient delivery of content through acontent delivery network (CDN) without taxing an origin server whilemaintaining fine grained location based access control. Requests to aCDN are augmented with quantized and non-quantized versions of locationinformation. A CDN can use quantized location information in a URI toidentify and return content if content corresponding to the URI isavailable in cache. If the content is not available in cache, the CDNcan contact an origin server to obtain a result for the request usingnon-quantized location information. The origin server examines thenon-quantized location information to determine whether to respond tothe client request with content. The origin server examines the areacorresponding to the quantized location information to determine whetherthe content should be cached at the CDN.

These and other features of the present invention will be presented inmore detail in the following specification of the invention and theaccompanying figures, which illustrate by way of example the principlesof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may best be understood by reference to the followingdescription taken in conjunction with the accompanying drawings, whichillustrate particular embodiments of the present invention.

FIG. 1 illustrates a particular example of a network that can use thetechniques and mechanisms of the present invention.

FIG. 2 illustrates a particular example of an origin server.

FIG. 3 illustrates a particular example of a client request.

FIG. 4 illustrates a particular example of a content delivery network(CDN) processing a client request.

FIG. 5 illustrates a particular example of redirect request.

FIG. 6 illustrates a particular example of a client device.

DESCRIPTION OF PARTICULAR EMBODIMENTS

Reference will now be made in detail to some specific examples of theinvention including the best modes contemplated by the inventors forcarrying out the invention. Examples of these specific embodiments areillustrated in the accompanying drawings. While the invention isdescribed in conjunction with these specific embodiments, it will beunderstood that it is not intended to limit the invention to thedescribed embodiments. On the contrary, it is intended to coveralternatives, modifications, and equivalents as may be included withinthe spirit and scope of the invention as defined by the appended claims.

For example, the techniques of the present invention will be describedin the context of particular devices such as mobile devices. However, itshould be noted that the techniques and mechanisms of the presentinvention can be used with a variety of devices including generalcomputing devices. In the following description, numerous specificdetails are set forth in order to provide a thorough understanding ofthe present invention. The present invention may be practiced withoutsome or all of these specific details. In other instances, well knownprocess operations have not been described in detail in order not tounnecessarily obscure the present invention.

Various techniques and mechanisms of the present invention willsometimes be described in singular form for clarity. However, it shouldbe noted that some embodiments include multiple iterations of atechnique or multiple instantiations of a mechanism unless notedotherwise. For example, a processor is used in a variety of contexts.However, it will be appreciated that multiple processors can also beused while remaining within the scope of the present invention unlessotherwise noted. Furthermore, the techniques and mechanisms of thepresent invention will sometimes describe two entities as beingconnected. It should be noted that a connection between two entitiesdoes not necessarily mean a direct, unimpeded connection, as a varietyof other entities may reside between the two entities. For example, aprocessor may be connected to memory, but it will be appreciated that avariety of bridges and controllers may reside between the processor andmemory. Consequently, a connection does not necessarily mean a direct,unimpeded connection unless otherwise noted.

Many organizations rely on content delivery networks (CDNs) toefficiently deliver content to clients. CDNs generally have the networkbandwidth and server capacity to scale up and down with client demand.It is often more economical for a content publisher to partner with aCDN to deliver content. Otherwise, the publisher may end upunderinvesting or overinvesting in hardware and network capacity.

CDNs typically function by receiving requests from clients, checking alocal cache for a copy of the requested resource, querying the originserver belonging to the publisher if the requested resource is missingfrom the cache or has expired, and then returning the resource to theclient and storing it in cache for use with future requests. CDN serversare typically strategically located at the edges of various networks tolimit loads on network interconnects and backbones. CDN servers areoften redundantly deployed and interact with other CDN servers torespond to content requests from clients and optimize content delivery.Optimization may include bandwidth usage reduction, latency reduction,and improved availability.

However, a shortcoming of CDNs is that they typically do not allow forfine-grained access-control to network resources. Once the content is incache, the function of access-control is left to the CDN. The accesscontrol systems employed by CDNs usually are meant to serve the greatestcommon denominator. This does not permit the fine-grained access-controlthat some organizations require.

Consequently, the techniques and mechanisms of the present inventionallow location based or geographically allocated resources to be cachedwithin a CDN while still permitting a fine-grained proprietary locationbased access-control algorithm to be applied by the origin server orcontent publisher. According to various embodiments, the CDN does notpossess any knowledge or proprietary algorithm details, or that aproprietary algorithm even exists.

Some CDNs support location and geolocation checks common to allcustomers of the CDN. The CDN will typically prevent access to resourcesunless they pass certain geolocation checks. These checks are oftenbased on source internet protocol (IP) address, which in a mobileenvironment is often unreliable. Other CDNs will rely entirely on anorigin server for fine-grained access-control to resources. Requestsreceived at a CDN server may be routed to an origin server forauthorization. However, routing numerous requests to an origin servereliminates many of the benefits of using a CDN in the first place.

According to various embodiments, a system for providing fine grainedlocation based access control includes an origin server, a CDN server,and a client. A client may be a mobile device, smartphone, computingsystem, etc. According to various embodiments, a client obtains locationfrom using services such as global positioning system (GPS), cell towertriangulation, wireless fidelity (WiFi), radio frequency identification(RFID), near field communication (NFC), etc. In particular embodiments,GPS longitude and latitude coordinates are obtained using device basedlocation application program interfaces (APIs). Using locationinformation, the client sends a request for content that gets routed toa CDN. In particular embodiments, the request is based on a quantizedversion of the latitude and longitude as reported by the device basedlocation APIs. For instance if the latitude and longitude is37.75098874, 122.47389284, the quantized latitude and longitude to onesignificant decimal point would be 37.8, 122.5.

According to various embodiments, the client request to the CDN wouldinclude the quantized latitude and longitude in a cacheable portion ofthe uniform resource locator (URL) or as query parameters of the URL. Itis recognized that the degree of quantization may vary. Queries withparticular quantized latitude and longitude values will correspond toparticular resources cached at the CDN. In particular embodiments, theclient request to the CDN would include the non-quantized latitude andlongitude in a non-cacheable portion of the request such as headers orthe query parameters of the URL. According to various embodiments, theCDN determines whether the content or resource is currently in cache.For example, the CDN would determine whether the content is currently incache by using a query that includes quantized location information 37.8and 122.5. If the resource such as media content is not cached, the CDNcontacts the origin server to obtain the result of the request. Thedetermination of whether a client is authorized to access locationrestricted content can be based on the more accurate non quantizedlatitude and longitude parameters at the origin server, while thedetermination is based on quantized latitude and longitude parameters atthe CDN server. The origin server may create an audit record indicatingthe requested resource, the time of request and the returned result. Theresult returned will indicate whether the CDN should cache the content.

According to various embodiments, the origin server determines whetherthe CDN should cache the content based on whether the region defined bythe quantized location information (e.g. 37.8 and 122.5) should haveaccess to a particular piece of content. In some examples, the regiondefined by 37.8 and 122.5 should have access and the origin serverinstructs the CDN to cache the content to allow the CDN to efficientlyrespond to queries with the quantized location coordinates 37.8 and122.5. In other examples, only part of the region defined by 37.8 and122.5 should have access to the content. The 37.8 and 122.5 area may bethe boundary region of a location based blackout zone. Consequently, theorigin server directs the CDN not to cache the content. Requests fromthe 37.8 and 122.5 areas are forwarded to the origin server whichhandles responding to the requests using more fine grained non-quantizedlongitude and latitude values.

If the content or resource corresponding to a query with quantizedlocation information is already cached, the content or resource issupplied from cache. The origin server may send a 302 re-direct with aquantized result with more accuracy or significant digits based on thenon-quantized supplied latitude and longitude parameters. Such 302re-direct responses are optional and could be repeated to obtain morefined grained cacheable results for boundary conditions of locationbased exclusion zones. According to various embodiments, content can bedelivered quickly and efficiently through a CDN without taxing theorigin server and without losing fine grained location based accesscontrol. This allows the CDN to excel in providing high capacity, highreliability, and low latency while allowing the publisher to maintainstrict control over the access to location restricted content.

FIG. 1 illustrates one example of a CDN that can be used with variousembodiments. According to various embodiments, a CDN 101 includes CDNservers 111, 113, 115, 117, and 119. In particular embodiments, CDNservers are strategically deployed to enhance content deliveryperformance. CDN servers may also be referred to surrogate servers orcontent replica servers. Effective CDN server placement may reduce thenumber of servers needed as well as the number of times content has tobe replicated. A variety of algorithms can be used to deploy CDNs.Greedy algorithms continually make locally optimal choices with the hopeof finding a global optimum. Hot spot algorithms place CDN servers nearthe clients generating the greatest load. Treebased algorithms specifythe locations of CDN servers to achieve particular levels ofperformance.

The number of CDN servers may vary from the dozens to thousands anddistribute content from origin server 121. Although an origin server 121may have very specific mechanisms for determining what clients haveaccess to particular pieces of content, once the content is distributedonto a CDN 101, the origin server 121 has limited access controlmechanisms. For example, client 131 may be authorized to accessparticular geographically restricted piece of content based on thelocation of the client 131 but a client 133 in a different geographicarea may not. Alternatively, different versions of content may beprovided to different geographic regions.

According to various embodiments, a client request for content istypically algorithmically directed at a CDN server that can efficientlyserver the client request. In order to verify that a particular client131 has access to a piece of geographically restricted content, arequest may be sent to an origin server 121 to perform locationverification. However, location verification is typically based oninternet protocol (IP) address, which is not a very accurate locationindicator, particularly for mobile devices.

FIG. 2 is a diagrammatic representation showing one example of an originserver 291. According to various embodiments, the origin server 291includes a processor 201, memory 203, and an interface. In someexamples, the interfaces include a program content interfaces, buyengine interfaces, carrier interfaces, etc., to allow the origin server291 the ability to interface with external entities including programcontent providers, carriers, vendors, billing systems, purchase engines,etc. The origin server 291 also can include a program content data store231 configured to store program content such as video clips, pay perview content, movies, programs, and live or near-live streams. Theorigin server 291 can also maintain static information such as icons andmenu pages.

An authentication module 221 verifies the identity of mobile devices.Location access control module 225 associated with authentication module221 determines a client location to determine whether the client hasaccess to a particular piece of content. For example, a location accesscontrol module may determine that a client while located in a geographicmarket X should not have access to a sports program. However, if theclient moves to a location in a geographic market Y, the client shouldhave access to the same sports program. Alternatively, the locationaccess control module may determine that a client in a geographic marketX should have access to a different news cast than a client in ageographic market Y even if the clients request the same piece of newsprogramming.

In many implementations without CDNs, the origin server 291 candetermine the location of the client using location informationassociated with the client. However, when CDNs distribute the content,CDNs typically do not allow for the same degree of access control andmay provide a client with requested content regardless of geographiclocation. Alternatively, the CDN may forward client requests for contentto an origin server 291 for the location access control module 225 tohandle location restrictions. However, forwarding requests to the originserver 291 removes some of the primary benefits of using CDNs.

A logging and report generation module 253 tracks mobile device requestsand associated responses. A monitor system 251 allows an administratorto view usage patterns and system availability. According to variousembodiments, the origin server 291 handles requests and responses formedia content related transactions and provides actual content. Inparticular embodiments, requests for content and actual contentdistribution can be handled by separate servers. In some embodiments,the origin server 291 can also be configured to provide media clips andfiles to a client in a manner that supplements a streaming server.

Although a particular origin server 291 is described, it should berecognized that a variety of alternative configurations are possible.For example, some modules such as a report and logging module 253 and amonitor 251 may not be needed on every server. Alternatively, themodules may be implemented on another device connected to the server. Inanother example, the server 291 may include a concrete buy engineimplementation. A variety of configurations are possible.

FIG. 3 illustrates a particular example of a client request. Accordingto various embodiments, a client request to a CDN includes a locationrestricted content identifier 301, quantized latitude and longitudeinformation in a cacheable portion 303 of the uniform resourceidentifier (URI), as well as non-quantized latitude and longitudeinformation in a non-cacheable portion 305. The cacheable portion may bethe path of the URI or query parameters of a uniform resource locator(URL). The non-cacheable portion may be a header or other queryparameters of the URL. According to various embodiments, the CDN mayhave content in cache to respond to a request including quantizedlongitude and latitude parameters. If the CDN has content to respond tothe request, the content is provided to the client. If the CDN does nothave content to respond to the request, the request is forwarded to anorigin server to determine whether the client should have access tolocation restricted content.

FIG. 4 illustrates a particular example of a CDN processing a clientrequest. According to various embodiments, the CDN determines whether aresource is currently in cache at 401. If the resource is not currentlyin cache, the CDN contacts the origin server at 403 to obtain the resultof the request. According to various embodiments, the determination isbased on the more accurate non-quantized latitude and longitudeparameters. At 405, the origin server creates an audit recordidentifying the requested resource, the time of the request, and thereturned result. At 407, the origin server determines whether thecontent should be cached at a CDN. According to various embodiments, theorigin server determines whether the geographic area defined by thequantized location value should have access to location restrictedcontent. In particular embodiments, the area defined by 39.5 and 122.8may fall entirely within a region that is allowed access to a particularsports program. The origin server returns the content to the CDN serverat 411 and indicates to the CDN that the content should be cached 413.The resource is then cached at 415. The content can then subsequently beprovided to any subscriber sending a request with the quantized locationparameters 39.5 and 122.8.

In other embodiments, only part of the area defined by 39.5 and 122.8should be allowed access to a particular piece of content 415. Accordingto various embodiments, the area may cover a boundary line thatseparates a blackout zone from a non-blackout zone. Consequently, theorigin server makes a determination of whether to send the content tothe client based on more precise non-quantized location parameters,returns the resource to the CDN at 417, and indicates to the CDN thatthe content should not be cached at 419. If the resource is cached at401, the result is supplied from cache at 421.

FIG. 5 illustrates one particular embodiment for sending redirectresponses to provide for access control with finer granularity.According to various embodiments, an origin server sends a redirect suchas a 302 re-direct at 501. The redirect has a quantized result with moreaccuracy or significant digits based on the non-quantized suppliedlatitude and longitude parameters. At 503, redirect responses arerepeated to obtain more fine grained cacheable results for boundaryconditions of location based exclusion zones. Location based blackoutsfor location restricted media content can be implemented with precision.In particular embodiments, different content can be provided todifferent clients based on quantized location information. At 505,metrics are maintained for cache hits based on finer grained cacheableresults. The level of granularity can be adjusted to provide foradditional granularity if there are excessive requests forwarded to anorigin server.

FIG. 6 illustrates one example of a server that can be used to providelocation based access control. According to particular embodiments, asystem 600 suitable for implementing particular embodiments of thepresent invention includes a processor 601, a memory 603, an interface611, and a bus 615 (e.g., a PCI bus or other interconnection fabric) andoperates as a streaming server. When acting under the control ofappropriate software or firmware, the processor 601 is responsible formodifying and transmitting live media data to a client. Variousspecially configured devices can also be used in place of a processor601 or in addition to processor 601. The interface 611 is typicallyconfigured to end and receive data packets or data segments over anetwork.

Particular examples of interfaces supports include Ethernet interfaces,frame relay interfaces, cable interfaces, DSL interfaces, token ringinterfaces, and the like. In addition, various very high-speedinterfaces may be provided such as fast Ethernet interfaces, GigabitEthernet interfaces, ATM interfaces, HSSI interfaces, POS interfaces,FDDI interfaces and the like. Generally, these interfaces may includeports appropriate for communication with the appropriate media. In somecases, they may also include an independent processor and, in someinstances, volatile RAM. The independent processors may control suchcommunications intensive tasks as packet switching, media control andmanagement.

According to various embodiments, the system 600 is a content serverthat also includes a transceiver, streaming buffers, and a programcontent database. The content server may also be associated withsubscription management, logging and report generation, and monitoringcapabilities. In particular embodiments, functionality for allowingoperation with mobile devices such as cellular phones operating in aparticular cellular network and providing subscription management.According to various embodiments, an authentication module verifies theidentity of devices including mobile devices. A logging and reportgeneration module tracks mobile device requests and associatedresponses. A monitor system allows an administrator to view usagepatterns and system availability. According to various embodiments, thecontent server 691 handles requests and responses for media contentrelated transactions while a separate streaming server provides theactual media streams.

Because such information and program instructions may be employed toimplement the systems/methods described herein, the present inventionrelates to tangible, machine readable media that include programinstructions, state information, etc. for performing various operationsdescribed herein. Examples of machine-readable media include hard disks,floppy disks, magnetic tape, optical media such as CD-ROM disks andDVDs; magneto-optical media such as optical disks, and hardware devicesthat are specially configured to store and perform program instructions,such as read-only memory devices (ROM) and programmable read-only memorydevices (PROMs). Examples of program instructions include both machinecode, such as produced by a compiler, and files containing higher levelcode that may be executed by the computer using an interpreter.

While the invention has been particularly shown and described withreference to specific embodiments thereof, it will be understood bythose skilled in the art that changes in the form and details of thedisclosed embodiments may be made without departing from the spirit orscope of the invention. It is therefore intended that the invention beinterpreted to include all variations and equivalents that fall withinthe true spirit and scope of the present invention.

What is claimed is:
 1. A method, comprising: receiving a resourcerequest from a client, the resource request received at a contentdelivery network server, the resource request including non-quantizedlocation coordinates and quantized location coordinates; parsing theresource request to identify quantized location coordinates; determiningwhether a location restricted resource is currently available in cacheby using the quantized location coordinates, wherein quantized locationcoordinates comprise latitude and longitude coordinates having fewersignificant digits than the non-quantized location coordinates.
 2. Themethod of claim 1, wherein the location restricted resource is locationrestricted media content.
 3. The method of claim 1, wherein quantizedlocation coordinates and the non-quantized location coordinates aredifferent versions of the same coordinates.
 4. The method of claim 1,wherein the quantized location coordinates are included in a cacheableportion of a uniform resource identifier.
 5. The method of claim 1,wherein the non-quantized location coordinates are included in anon-cacheable portion of the resource request.
 6. The method of claim 5,wherein the non-quantized location coordinates are included in queryparameters of a uniform resource locator.
 7. The method of claim 1,wherein the quantized location coordinates are used to determine whetherthe client has access to the location restricted resource when thelocation restricted resource is available in a content delivery networkserver cache.
 8. The method of claim 1, wherein the content deliverynetwork server contacts an origin server to obtain the locationrestricted resource when the location restricted resource is notavailable in a content delivery network server cache, wherein the originserver provides the location restricted resource based on non-quantizedlatitude and longitude parameters.
 9. The method of claim 8, wherein theorigin server creates an audit record identifying the resource request,a request time, and the location restricted resource.
 10. The method ofclaim 8, wherein the origin server returns the location restrictedresource to the content delivery network server and indicates whetherthe location restricted resource should be cached.
 11. The method ofclaim 8, wherein the origin server indicates to the content deliverynetwork server that the location restricted resource should be cached ifthe region defined by the quantized location coordinates falls entirelywithin a non-restricted zone.
 12. The method of claim 8, wherein theorigin server indicates to the content delivery network server that thelocation restricted resource should not be cached if the region definedby the quantized location coordinates falls partially within anon-restricted zone.
 13. A system, comprising: an interface configuredto receive a resource request from a client, the resource requestreceived at a content delivery network server, the resource requestincluding non-quantized location coordinates and quantized locationcoordinates; a processor configured to parse the resource request toidentify quantized location coordinates and determine whether a locationrestricted resource is currently available in cache by using thequantized location coordinates, wherein quantized location coordinatescomprise latitude and longitude coordinates having fewer significantdigits than the non-quantized location coordinates.
 14. The system ofclaim 13, wherein the location restricted resource is locationrestricted media content.
 15. The system of claim 13, wherein quantizedlocation coordinates and the non-quantized location coordinates aredifferent versions of the same coordinates.
 16. An apparatus,comprising: means for receiving a resource request from a client, theresource request received at a content delivery network server, theresource request including non-quantized location coordinates andquantized location coordinates; means for parsing the resource requestto identify quantized location coordinates; means for determiningwhether a location restricted resource is currently available in cacheby using the quantized location coordinates, wherein quantized locationcoordinates comprise latitude and longitude coordinates having fewersignificant digits than the non-quantized location coordinates.